The teen can be heard in videos of the incident claiming that the officer made an offensive comment to a female friend of his.

"I didn't do anything to hurt you. All I said was to respect the girl. You told her to 'get off my property you piece of (expletive),'" the teen is heard telling the officer in the videos.

The situation between the officer and the boy turned physical, with several other juveniles joining in, Anaheim police said.

Video shows a teen pushing the officer, who falls over some bushes, but does not let go of the teenager.

As more teens approached, the officer pulled his gun and fired once. No one was injured.

"That was the most frightening part of it all," the teen's mother said. "What if that bullet would have been a couple inches closer."

The circumstances surrounding the firing of the weapon were being investigated by the Anaheim Police Department's Homicide Detail.

The 13-year-old boy was arrested and booked at Orange County Juvenile Hall for criminal threats and battery. A 15-year-old boy was also arrested for assault and battery and was released to his parents.

After watching the videos, the 13-year-old boy's mother said she felt he did the right thing.

"I didn't see him being aggressive. I saw him remaining as calm as he possibly could. I saw him trying to reason with the adult," she told Eyewitness News.

The case is set to be presented to the Orange County District Attorney's Office when it is completed. The names of those involved in the incident were not released.

The ACLU was among those expressing criticism of the officer's behavior in the incident.

"An officer, even off duty, has an obligation to follow the law and protect public safety, rather than threaten it," said Jennifer Rojas, an official with the ACLU of Southern California. "The LAPD officer's actions on the video are grossly irresponsible."

The Los Angeles Police Department is conducting its own internal investigation into the actions of the officer, Anaheim police said.

Anaheim Mayor Tom Tait said Wednesday the city is committed to a "thorough, impartial investigation" of the incident.

"Like many in the community, I've seen the video and I'm very concerned about what it shows," Tait said. "Anaheim is committed to a full and impartial investigation. Our city will move forward without delay."

Tait and Anaheim Police Chief Raul Quezada are expected to speak about the investigation during a press conference Thursday.